Do you have troubles with multiplication? Below the video is a demonstration of an easy way to multiply large numbers together. How long has this method been known? Why were we never taught this when we were kids?

Interesting. You’d have to use stub lines/points to represent the zeroes, but it’s doable. I just worked out 101 x 101 & for added confirmation, 2301 x 101. The trick then becomes knowing where to draw those grouping curves.

Actually, one could conceivably use this format for representing numbers in a handwritten cipher and really mess with folks. Say, do the usual 1-26 for representing A-Z, then break words into letter pairs, and then write it out as line-multiples of the pairs. I suppose you could also pre-encode as ROT-13 to really obfuscate things.

That might be something for me to do to my D&D group the next time I’m DM….

Well, yes, that makes sense. You’re just doing the exact same thing you would when you multiply, but visually. Then again, some kids are visual learners, and this might help them understand multiplication – it’s more fun than looking at numbers.

What’s to prove? All it does is a ‘dot’ style of multiplication as opposed to writing numbers and having to do the math in your head first.

By making it a diagonal on its corner, you quickly see how many digits the end result should have (in the second example, it was 5 because there were 5 diagonals) In effect, you’re not doing anything that ‘long’ multiplication never taught you, you’re just doing it by counting dots laid out in a certain way rather than writing down the Arabic numerals.